Resources

Number to string

Integer or float

const myNumber = 123
myNumber.toString()
// "123"

Optionally supply 10 as the base.

Note that a method directly on number (without a variable declared first) will give an error.

123.toString()
// Uncaught SyntaxError: Invalid or unexpected token

String to number

Remember that JavaScript as no Int and Float types, just Number.

To integer

parseInt("123")
// 123

parseInt("123.45")
// 123

No effect if already an integer.

parseInt(123)
// 123

Recommended - pass the radix argument as the base, to avoid linting errors. The base can be inferred, but in some cases will be incorrect so it is better to always set it. See Other number systems section below for other uses of this argument.

parseInt("123", 10)
// 123

parseInt("123.45", 10)
// 123

To float

parseFloat("123.45")
// 123.45

parseFloat("123")
// 123

No change on float input.

parseFloat(123.45)
// 123.45

Other number systems

The base or radix defaults to 10 but you can specify others.

Parse base 2

parseInt("10", 2)
// 2

Parse hexidecimal

> parseInt("f", 16)
15

> parseInt("0xf")
15

Number base 2 sting

const myNumber = 10

myNumber.toString(2)
// '1010'

Number to base 16 string

const myNumber = 10

myNumber.toString(16)
// 'a'